For those who want it, Canon is now offering a modification that would lock the mode dials for the EOS 5D Mark II and EOS 7D DSLR cameras.

This modification is available, for a $100 fee, to owners of these cameras who would prefer a Mode Dial which locks in place and can’t be accidentally moved during normal camera operation. Canon says the modification will remain an upgrade and will not become standard on new EOS 7D and EOS 5D Mark II camera’s leaving the factory.

Once modified, users must first press and hold down the central lock-release button in order to turn the Mode Dial. The modification is intended to prevent the Mode Dial from accidentally moving, once set to a particular exposure mode by the user.